Machine for removing water from



0. QVILLER Sept. 5, 1939.

MACHINE FOR REMOVING WATER FROM PULP, CELLULOSEL AND THE LIKE Or i ginal Filed June 26, 1934 Reissued- Sept. s, 1939 ration oi Illinois In order to increase the producing capacity oi water removing machines (strainer drums) for wood pulp, cellulose and the like pulps, constructions have been devised, wherein some parts of the space below the sieve cloth oi the drum is subjected to a reduced pressure. The sieve drum is made with a series or cells under the sieve cloth. During the rotation of the drum these cells are connected successively and automatically with a suction pipe. The connection with the suction pipe is interrupted at the place on the drum, where the pulp layer is removed or cut oil, whereupon the. connection is reestablished at a suitable place, where the sieve cloth shows the drawback that the speed with which the machine can operate is highly limited. In order to remove this drawback partly, it has been proposed to maintain under a suitable reduced 29 pressure the whole space inside the sieve drum by means of agsuctionbox arranged at the point, where the pulp layer is removedirom 'the drum.

5 construction, however, has shown other in-, conveniences, because the pulp layer has to be 5 scraped oil! in 9. Compartment under a lower presbacks appearing usually just at the point of scraping o? the layer.

- The present invention makes use 01 the well- 30 known arrangement, wherein the drum on the upwardly travelling side between the pulp level and the place of scraping oil is covered on its outside by a stationary, upstanding cap, hood or the like, and the space between same and the 35 drum circumference is subjected to a pressure which is higher than the atmospheric pressure. According to the invention the space between the drum and the portion or the drum container below the scraping-oil point is open to theato mosphere. Further, the increased pressure prevailing in the cap or the like-is maintained at so .high a value that it presses the pulp level in the container part facing to the down-travelling por- 45 cated at 'a short distance under the scrapingoil! point. A, loaded, elastic tightening scraper may be arranged on the cap with its tightening line located at the scraping-oil point.

The accompanying drawing shows invertical so cross section two embodiments of the machine.

struction as an ordinary drum covered on its periphery with a filtering sieve cloth I. The drum is immersed partly in a container I having 85 a pulp supply 4. A roll 5 presses against the \5 is covered with a pulp layer. Such a cell system sure than that of the atmosphere, and the draw tion of the drum periphery up to a height lo-v "I'he sieve drum I may be of the same con- .U T D sr-Ares PATENT orrlcs' MACHINE 'ron REMOVING ws'rsa mo PULP, osnwnoss. sun-ma use Olaf Qviller, Oslo, Norway,- assignor to Fibre 'Making Processes, Inc.

Chicago, 111., a corpo- Original No. 1,995,011, dated March 19, 1935, Se-

rial No. 732,548, June 26, 1934. for reissue December 19, 1938, Serial No. 248,008. In Sweden July 6, 1933 4 claims. (Ci. 92-43) Application pulp layer 8 to dehydrate same to a suitable de-" gree and to remove it from the drum periphery at the scraping-oil" point I. A tight topjportion I in the form of a cap, hood or the like is arranged above the upwardly travelling portion of the 5 v subjectedby means of a. suitable air compressor (not shown) to an increasedpressure', air being pressed into said compartment through a pipe II or the like.

i The pressure cap I is tightened at I! against the press roller 5 and likewise against the drum gables by means of side flanges it, but the cap is open to the bottom side facing to the container bottom, because here the tightening is eilected by the pulp contained in the lower part of compartment 9 outside the's ieve drum. The

space formed between the container 3 and the I downwardly travelling drum portion may be in connection with the atmosphere. v

The pulp layer 6 liited out from the drum 2 by the roll 5 or scraped of! therefrom at In follows with the roll and is removed by a scraper i4 loaded by a weight. Immediately under the point ill a scraper I5 is arranged to clean the sieve cloth.

The increased pressure in the cap determines the height I 8 to which the pulp level is pressed up in the container 3. This level is so adjusted that between the layer removing point i0 and the subiacent longitudinal line H of the drum periphery, where the "same again enters into the pulp there is a narrow longitudinal periphery S5 portion open to the atmosphere and through which air from inside the drum may escape.

The water passing through the layer and sieve cloth into the drum is removed in ordinary manner by suction pipes II and is received in a sump ll.

Fig. 2 shows the upper portion of another embodiment, wherein the press roll 5 is dispensed with and replaced by a loaded, elastic sealing member or doctor 20 providing for the tightening between the pressure cap I and the layer 6 at its removing point ll.

'-Another advantage oi this arrangement re- ,sides in the pressure prevailing in the cap I relieving the doctor 20 to prevent the layer from forming longitudinal folds, ii the layer increases in thickness in case the. pressure inside the com-. partment 9 increases owing to variations in the air pressure supplied by the compressor or fan.

The foremost closing or the pressure compart- Q ment 0 may obviously be located somewhat periphery considered) the removing point. Thus according to Fig. 2 this point may be displaced forwards on to' the contacting edge of the scraper ll instead of being located at iii, and this will apply. it the interior drum pressure is not higher than atmosphere pressure. Further. the exterior pressure between the point l0 and the level point iI need not beso low as atmospheric pressure, provided it is only considerably lower than the pressure prevailing in compartment 8.

' I claim: a

1. A machine for removing water from wood pulp, cellulose or the like, comprising a container for the pulp, a rotating drum partly immersed in the pulp and provided on its periphery-with a sieve cloth, said drum presenting'at any time a peripheral portion traveling upwards in the pulp and another peripheral portion traveling downwards in the pulp and also presenting a non-immersed peripheral portion, means for removing the pulp layer from the drum periphery at a point above the pulp level, a stationary cap covering air-tightly the non-immersed peripheral portion 01 the drum between the pulp level and a point at or behind the layer removing point, and means for subjecting the compartment inside the cap between the latter and the drum to an increased pressure higher than atmospheric pressure, the pressure between the drum and the container below the layer removing point, where the drum periphery enters the pulp, being considerably lower than that prevailing in the cap.

2. A machine for removing water from wood pulp, cellulose or the like, comprising a container for the pulp, a rotating drum partly in the pulp and provided on its periphery with a sieve cloth, said drum presenting at any time a peripheral portion traveling upwards in the pulp and another peripheral portion traveling downwards in the pulp and also presenting a non-immersed peripheral portion, means "ior removing the pulp layer from the drum periphery at a point above the pulp level, a stationary cap covering air-tightly the non-immersed peripheral portion of the drum between the pulp level and a point at or behind the layer removing point, and means i'or subjecting the compartment inside the cap between the latter and the drum to an increased pressure higher than atmospheric pressure, the pressure between the drum and the container below the'layer removing point, where the drum periphery enters the pulp, being considerably lower than that prevailing in the cap, the means for producing an increased pressure inside the go cap being so adjusted as to maintain therein a pressure forcing the pulp level on the downwardly traveling drum periphery up to a height shortly below the layer removing point.

3. A-machine according to claim 1, wherein a loaded, elastic sealing member is arranged to contact with the pulp layer on the drum periphery at or behind the layer removing point in such a manner as to seal the cap at this point.

4. A machine according to claim 2, wherein a loaded, elastic sealing member is arranged to contact with the pulp layer on the drum periphery at or behind the layer removing point in such a manner as to seal the cap at this point.

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